package org.owasp.webgoat;

import java.io.IOException;
import java.io.PrintWriter;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Enumeration;
import java.util.List;
import java.util.Locale;
import java.util.TimeZone;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.owasp.webgoat.lessons.AbstractLesson;
import org.owasp.webgoat.lessons.WelcomeScreen;
import org.owasp.webgoat.lessons.admin.WelcomeAdminScreen;
import org.owasp.webgoat.session.Course;
import org.owasp.webgoat.session.ErrorScreen;
import org.owasp.webgoat.session.Screen;
import org.owasp.webgoat.session.UserTracker;
import org.owasp.webgoat.session.WebSession;

/*******************************************************************************
 * 
 * 
 * This file is part of WebGoat, an Open Web Application Security Project
 * utility. For details, please see http://www.owasp.org/
 * 
 * Copyright (c) 2002 - 2007 Bruce Mayhew
 * 
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option) any later
 * version.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place - Suite 330, Boston, MA 02111-1307, USA.
 * 
 * Getting Source ==============
 * 
 * Source for this application is maintained at code.google.com, a repository
 * for free software projects.
 * 
 * For details, please see http://code.google.com/p/webgoat/
 * 
 * 
 * @author Jeff Williams <a href="http://www.aspectsecurity.com">Aspect Security</a>
 * @author Bruce Mayhew <a href="http://code.google.com/p/webgoat">WebGoat</a>
 * @created October 28, 2003
 */
public class HammerHead extends HttpServlet
{

    /**
     * Description of the Field
     */
    protected static SimpleDateFormat httpDateFormat;

    /**
     * Description of the Field
     */
    protected WebSession mySession;

    /**
     * Set the session timeout to be 2 days
     */
    private final static int sessionTimeoutSeconds = 60 * 60 * 24 * 2;

    // private final static int sessionTimeoutSeconds = 1;

    /**
     * Properties file path
     */
    public static String propertiesPath = null;


    /**
     * Description of the Method
     * 
     * @param request
     *        Description of the Parameter
     * @param response
     *        Description of the Parameter
     * @exception IOException
     *            Description of the Exception
     * @exception ServletException
     *            Description of the Exception
     */
    public void doGet(HttpServletRequest request, HttpServletResponse response)
	    throws IOException, ServletException
    {
	doPost(request, response);
    }


    /**
     * Description of the Method
     * 
     * @param request
     *        Description of the Parameter
     * @param response
     *        Description of the Parameter
     * @exception IOException
     *            Description of the Exception
     * @exception ServletException
     *            Description of the Exception
     */
    public void doPost(HttpServletRequest request, HttpServletResponse response)
	    throws IOException, ServletException
    {
	Screen screen = null;

	try
	{
	    // System.out.println( "HH Entering doPost: " );
	    // System.out.println( " - HH request " + request);
	    // System.out.println( " - HH principle: " +
	    // request.getUserPrincipal() );
	    // setCacheHeaders(response, 0);
	    ServletContext context = getServletContext();

	    // FIXME: If a response is written by updateSession(), do not
	    // call makeScreen() and writeScreen()
	    mySession = updateSession(request, response, context);
	    if (response.isCommitted())
		return;

	    // Note: For the lesson to track the status, we need to update
	    // the lesson tracker object
	    // from the screen.createContent() method. The create content is
	    // the only point
	    // where the lesson "knows" what has happened. To track it at a
	    // latter point would
	    // require the lesson to have memory.
	    screen = makeScreen(mySession); // This calls the lesson's
	    // handleRequest()
	    if (response.isCommitted())
		return;

	    // if the screen parameter exists, the screen was visited via
	    // the menu categories,
	    // we won't count these as visits. The user may be able to
	    // manipulate the counts
	    // by specifying the screen parameter using a proxy. Good for
	    // them!
	    String fromMenus = mySession.getParser().getRawParameter(
		    WebSession.SCREEN, null);
	    if (fromMenus == null)
	    {
		// if the show source parameter exists, don't add the visit
		fromMenus = mySession.getParser().getRawParameter(
			WebSession.SHOW, null);
		if (fromMenus == null)
		{
		    screen.getLessonTracker(mySession).incrementNumVisits();
		}
	    }

	    // log the access to this screen for this user
	    UserTracker userTracker = UserTracker.instance();
	    userTracker.update(mySession, screen);
	    log(request, screen.getClass().getName() + " | "
		    + mySession.getParser().toString());

	    // Redirect the request to our View servlet
	    String userAgent = request.getHeader("user-agent");
	    String clientBrowser = "Not known!";
	    if (userAgent != null)
	    {
		clientBrowser = userAgent;
	    }
	    request.setAttribute("client.browser", clientBrowser);
	    request.getSession().setAttribute("websession", mySession);
	    request.getSession().setAttribute("course", mySession.getCourse());

	    request.getRequestDispatcher(getViewPage(mySession)).forward(
		    request, response);
	}
	catch (Throwable t)
	{
	    t.printStackTrace();
	    log("ERROR: " + t);
	    screen = new ErrorScreen(mySession, t);
	}
	finally
	{
	    try
	    {
		this.writeScreen(screen, response);
	    }
	    catch (Throwable thr)
	    {
		thr.printStackTrace();
		log(request, "Could not write error screen: "
			+ thr.getMessage());
	    }
	    // System.out.println( "HH Leaving doPost: " );
	}
    }


    private String getViewPage(WebSession webSession)
    {
	String page;

	// If this session has not seen the landing page yet, go there instead.
	HttpSession session = webSession.getRequest().getSession();
	if (session.getAttribute("welcomed") == null)
	{
	    session.setAttribute("welcomed", "true");
	    page = "/webgoat.jsp";
	}
	else
	    page = "/main.jsp";

	return page;
    }


    /**
     * Description of the Method
     * 
     * @param session
     *        Description of the Parameter
     */
    private void dumpSession(HttpSession session)
    {
	Enumeration enumerator = session.getAttributeNames();

	while (enumerator.hasMoreElements())
	{
	    String name = (String) enumerator.nextElement();
	    Object value = session.getAttribute(name);
	    System.out.println("Name: " + name);
	    System.out.println("Value: " + value);
	}
    }


    /**
     * Description of the Method
     * 
     * @param date
     *        Description of the Parameter
     * @return RFC 1123 http date format
     */
    protected static String formatHttpDate(Date date)
    {
	synchronized (httpDateFormat)
	{
	    return httpDateFormat.format(date);
	}
    }


    /**
     * Return information about this servlet
     * 
     * @return The servletInfo value
     */
    public String getServletInfo()
    {
	return "WebGoat is sponsored by Aspect Security.";
    }


    /**
     * Return properties path
     * 
     * @return servlet context path + WEB_INF
     */
    public void init() throws ServletException
    {
	httpDateFormat = new SimpleDateFormat("EEE, dd MMM yyyyy HH:mm:ss z",
		Locale.US);
	httpDateFormat.setTimeZone(TimeZone.getTimeZone("GMT"));
	propertiesPath = getServletContext().getRealPath(
		"." + System.getProperty("file.separator") + "WEB-INF"
			+ "/webgoat.properties");
    }


    /**
     * Description of the Method
     * 
     * @param request
     *        Description of the Parameter
     * @param message
     *        Description of the Parameter
     */
    public void log(HttpServletRequest request, String message)
    {
	String output = new Date() + " | " + request.getRemoteHost() + ":"
		+ request.getRemoteAddr() + " | " + message;
	log(output);
	System.out.println(output);
    }


    public List getCategories()
    {
	Course course = mySession.getCourse();

	// May need to clone the List before returning it.
	// return new ArrayList(course.getCategories());
	return course.getCategories();
    }


    /*
     * public List getLessons(Category category, String role) { Course
     * course = mySession.getCourse(); // May need to clone the List before
     * returning it. //return new ArrayList(course.getLessons(category,
     * role)); return course.getLessons(category, role); }
     */

    /**
     * Description of the Method
     * 
     * @param s
     *        Description of the Parameter
     * @return Description of the Return Value
     */
    protected Screen makeScreen(WebSession s)
    {
	Screen screen = null;
	int scr = s.getCurrentScreen();
	Course course = s.getCourse();

	if (s.isUser() || s.isChallenge())
	{
	    if (scr == WebSession.WELCOME)
	    {
		screen = new WelcomeScreen(s);
	    }
	    else
	    {
		AbstractLesson lesson = course.getLesson(s, scr,
			AbstractLesson.USER_ROLE);
		if (lesson == null && s.isHackedAdmin())
		{
		    // If admin was hacked, let the user see some of the
		    // admin screens
		    lesson = course.getLesson(s, scr,
			    AbstractLesson.HACKED_ADMIN_ROLE);
		}

		if (lesson != null)
		{
		    screen = lesson;

		    // We need to do some bookkeeping for the hackable admin
		    // interface.
		    // This is the only place we can tell if the user
		    // successfully hacked the hackable
		    // admin and has actually accessed an admin screen. You
		    // need BOTH pieces of information
		    // in order to satisfy the remote admin lesson.

		    s.setHasHackableAdmin(screen.getRole());

		    lesson.handleRequest(s);
		    s.setCurrentMenu(lesson.getCategory().getRanking());
		}
		else
		{
		    screen = new ErrorScreen(s,
			    "Invalid screen requested.  Try: http://localhost/WebGoat/attack");
		}
	    }
	}
	else if (s.isAdmin())
	{
	    if (scr == WebSession.WELCOME)
	    {
		screen = new WelcomeAdminScreen(s);
	    }
	    else
	    {
		// Admin can see all roles.
		// FIXME: should be able to pass a list of roles.
		AbstractLesson lesson = course.getLesson(s, scr,
			AbstractLesson.ADMIN_ROLE);
		if (lesson == null)
		{
		    lesson = course.getLesson(s, scr,
			    AbstractLesson.HACKED_ADMIN_ROLE);
		}
		if (lesson == null)
		{
		    lesson = course.getLesson(s, scr, AbstractLesson.USER_ROLE);
		}

		if (lesson != null)
		{
		    screen = lesson;

		    // We need to do some bookkeeping for the hackable admin
		    // interface.
		    // This is the only place we can tell if the user
		    // successfully hacked the hackable
		    // admin and has actually accessed an admin screen. You
		    // need BOTH pieces of information
		    // in order to satisfy the remote admin lesson.

		    s.setHasHackableAdmin(screen.getRole());

		    lesson.handleRequest(s);
		    s.setCurrentMenu(lesson.getCategory().getRanking());
		}
		else
		{
		    screen = new ErrorScreen(
			    s,
			    "Invalid screen requested.  Try Setting Admin to false or Try: http://localhost/WebGoat/attack");
		}
	    }
	}

	return (screen);
    }


    /**
     * This method sets the required expiration headers in the response for
     * a given RunData object. This method attempts to set all relevant
     * headers, both for HTTP 1.0 and HTTP 1.1.
     * 
     * @param response
     *        The new cacheHeaders value
     * @param expiry
     *        The new cacheHeaders value
     */
    protected static void setCacheHeaders(HttpServletResponse response,
	    int expiry)
    {
	if (expiry == 0)
	{
	    response.setHeader("Pragma", "no-cache");
	    response.setHeader("Cache-Control", "no-cache");
	    response.setHeader("Expires", formatHttpDate(new Date()));
	}
	else
	{
	    Date expiryDate = new Date(System.currentTimeMillis() + expiry);
	    response.setHeader("Expires", formatHttpDate(expiryDate));
	}
    }


    /**
     * Description of the Method
     * 
     * @param request
     *        Description of the Parameter
     * @param response
     *        Description of the Parameter
     * @param context
     *        Description of the Parameter
     * @return Description of the Return Value
     */
    protected WebSession updateSession(HttpServletRequest request,
	    HttpServletResponse response, ServletContext context)
	    throws IOException
    {
	HttpSession hs;
	hs = request.getSession(true);

	// System.out.println( "HH Entering Session_id: " + hs.getId() );
	// dumpSession( hs );
	// Get our session object out of the HTTP session
	WebSession session = null;
	Object o = hs.getAttribute(WebSession.SESSION);

	if ((o != null) && o instanceof WebSession)
	{
	    session = (WebSession) o;
	}
	else
	{
	    // Create new custom session and save it in the HTTP session
	    // System.out.println( "HH Creating new WebSession: " );
	    session = new WebSession(this, context);
	    hs.setAttribute(WebSession.SESSION, session);
	    // reset timeout
	    hs.setMaxInactiveInterval(sessionTimeoutSeconds);

	}

	session.update(request, response, this.getServletName());

	// to authenticate
	// System.out.println( "HH Leaving Session_id: " + hs.getId() );
	// dumpSession( hs );
	return (session);
    }


    /**
     * Description of the Method
     * 
     * @param s
     *        Description of the Parameter
     * @param response
     *        Description of the Parameter
     * @exception IOException
     *            Description of the Exception
     */
    protected void writeScreen(Screen s, HttpServletResponse response)
	    throws IOException
    {
	response.setContentType("text/html");

	PrintWriter out = response.getWriter();

	if (s == null)
	{
	    s = new ErrorScreen(mySession, "Page to display was null");
	}

	// set the content-length of the response.
	// Trying to avoid chunked-encoding. (Aspect required)
	response.setContentLength(s.getContentLength());
	response.setHeader("Content-Length", s.getContentLength() + "");

	s.output(out);
	out.close();
    }
}
